English Wednes (in Wednes-day) is not an exact cognate but rather continues Common Germanic *Wōdinaz, pre-Germanic *Wātenos. (Old Norse Óðinn, however, due to its lack of umlaut, appears to continue *Wōdanaz and the replacement of the suffix vowel appears to be secondary.)

This suggests a variation of the theonym in early Germanic, *Wōdanaz vs. *Wōdinaz. The form with -i- appears to have been present in Frisia. The situation in Old English is unclear. The attested Old English forms point to *Wōdanaz, but i-umlauted forms surface in records after the end of the Old English period. Thus, wōdnesdæġ is replaced by continuations of *wēdnesdæġ around AD 1200.
The same transition to the umlauted form of the theonym during the 12th or early 13th century (early Middle English) is also found in English placenames, such as Wensley (Wednesleg ca. 1212, earlier Wodnesleie), Wednesbury (Wednesbiri 1227, earlier Wadnesberie, Wodnesberia), Wednesfield (Wednesfeld 1251, earlier Wodnesfelde).